Inserter systems, such as those applicable for use with the present invention, are mail processing machines typically used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee.
In many respects, the typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (other sheets, enclosures, and envelopes) enter the inserter system as inputs. Then, a variety of modules or workstations in the inserter system work cooperatively to process the sheets until a finished mail piece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.
Typically, inserter systems prepare mail pieces by gathering collations of documents on a conveyor. The collations are then transported on the conveyor to an insertion station where they are automatically stuffed into envelopes. After being stuffed with the collations, the envelopes are removed from the insertion station for further processing. Such further processing may include automated closing and sealing the envelope flap, weighing the envelope, applying postage to the envelope, and finally sorting and stacking the envelopes.
The input stages of a typical inserter system are depicted in FIG. 1a. Rolls or stacks of continuous printed documents, called a web, are provided at a web supply and fed into a web cutter where the continuous web is cut into individual sheets. In some inserter systems, the input stages of an inserter also include a right-angle turn (RAT) to allow the individual pages to change their moving direction before they are fed into the inserter, as shown in FIG. 1b. The present invention is primarily related to an inserter system having a RAT.
In general, web material is driven in move-and-pause cycles, wherein the web material is temporarily paused for a short period to allow the cutter to cut the material into cut sheets. Thus, in each cycle, the web must be accelerated and decelerated. FIG. 2 illustrates the input stages of an inserter system. As shown in FIG. 2, the web material 5 is driven continuously by a web driver 100 into a cutter module 200. The cutter module 200 has a cutter 210, usually in a form of a guillotine cutting blade, to cut the web material 5 crosswise into separate sheets 8.
FIG. 3 is a schematic representation of a web cutter for splitting a web into two side-by-side portions before separating the web into individual sheets. This arrangement utilizes a right-angle turn (RAT) 309. The web material 5 is split into two side-by-side portions by a cutting device 312. The cutting device 312 may be a stationary knife or a rotating cutting disc. After the web material 5 is split into two side-by-side portions, it is cut crosswise by the guillotine cutter 210 into pairs of sheets 321 and 322. The sheets 321 and 322 move side-by-side toward the right angle turn device 309 so that they can then move in tandem (or with some overlap) into an inserter system.
The high productivity arrangements currently in use, which provide high system throughput performance, will be limited for cut sheets with high aspect ratios (sheet length divided by sheet width). Such sheets must pass enter the inserter system more slowly, and therefore must pass through the right-angle turn (RAT) at a lower speed than cut sheets having higher aspect ratios. Because a cut sheet having a high aspect ratio must enter the RAT at a lower speed, a tip to tail crash at the exit of the cutting device 210 will occur. In other words, the tip of the paper web will collide with the tail of a cut sheet. On older equipment which processes all cut sheets at much slower rates, this problem does not exist.